In recent years, a cutting tool having a longer tool life than in the case of a conventional cutting tool has been required, along with the improvement of highly efficient cutting. Thus, in terms of the performance required for tool materials, improvements of wear resistance and fracture resistance, which are directly related to the tool life, have been becoming increasingly important. In order to improve such characteristics, a coated cutting tool is used in which coatings are laminated in an alternating manner on a surface of a substrate.
Various techniques have been proposed in order to improve the characteristics of the above-described alternating laminate coatings. For example, Patent Document 1 proposes a coated cutting tool in which: compounds of two kinds, i.e., TixAl1-xN and TiyAl1-yN (0≤x<0.5, 0.5<y≤1) are laminated in an alternating manner; and the resulting laminate is aluminum rich in its entirety.